R4/industrial tires are six ply or greater.
I cannot think of any conditions in Northern Virginia likely to cause punctures through six plies.
I would not slime front tires.
We've got plenty of nasty thorns & briars but I wouldn't think they would puncture a tire. It's the Autumn Olives, Locusts, Hawthornes, & jagged rocks that concern meNo nails or construction debris, but I'm still on the fence.
I have many locusts.
I detest Slime, but it is the only way I can keep air in my JD 19HP lawn tractor front tires.